Magnesium Complexes Research Articles

A Constrained Geometry Fluorenyl Amido Magnesium Catalyst for Amine‐Borane Dehydrocoupling

AbstractA fluorenyl amido constrained geometry magnesium complex is described, which was obtained by deprotonation of the corresponding neutral ligand system with dibutyl magnesium. Its structure was determined by SC‐XRD and it was shown to be a potent catalyst for amine‐borane dehydrogenation/dehydrocoupling.

In-silico Studies, Synthesis, and Antacid Activities of Magnesium (II) Complexes.

Nowadays, acidity is a severe problem worldwide caused by excessive gastric acid secretion by the stomach and proximal intestine. Antacids are drugs capable of buffering stomach acid. Therefore, in our research work, we have reported the in-silico studies, synthesis, characterization, and evaluation of antacid activities of magnesium (II) complexes via the acid-base neutralization process. In this research, some magnesium complexes were synthesized and their antacid behavior was compared with marketed products. Also, in-silico studies were performed on H+/K+ ATPase (Proton pump). All synthesized compounds were characterized by various spectroscopic techniques like UV-Vis, FT-IR, XRD, and DSC techniques. Spectroscopic analysis results showed that the semicarbazone ligand shows keto-enol isomerism and forms a coordinated stable complex with magnesium ions in the crystalline phase. The FT-IR results confirmed the presence of Mg-O stretching, N-H bending, and C=N stretching vibrations in Mg (II) complexes. The antacid activities of Mg (II) complexes were excellent as compared to the semicarbazone ligand and comparable with that of marketed antacid drugs like ENO, and Pantop-D. Insilco studies also confirmed that semicarbazone ligand and its Mg (II) complexes were both found to be fitted into the active sites of molecular targets, and Mg (II) complexes showed better binding affinities towards macromolecular as compared to semicarbazone ligand.

Magnesium 4, 5, and 6 coordinate complexes with ligands bound via sp or sp2 hybridized atoms

As a metallic element of high natural abundance, magnesium finds a wide range of uses in both stoichiometric and more recently catalytic applications. This often takes advantage of the basic or nucleophilic properties of its compounds or their ability to co-complex with other organometallic compounds. However, the homoleptic chemistry of Mg(II) is heavily skewed towards alkyl and aryl ligands bound via sp2 and sp3 hybridized atoms. Here, we report our combined NMR spectroscopic and X-ray crystallographic study into much rarer alternative THF solvates of homoleptic magnesium complexes using ligands which bind via sp (alkynyl) and sp2 (imido) atoms. Specifically, we exploit the high acidity of terminal alkynes and diphenylacetonitrile to prepare tetra-solvated distorted octahedral complexes Mg(CCC6H4R-p)2(THF)4 (R = Me, CF3) and Mg(NCCPh2)2(THF)4 starting from the commercial alkyl reagent MgBu2. Adopting a similar deprotonative strategy using benzophenoneimine Ph2CNH affords the heteroleptic trinuclear complex Mg3(NCPh2)4nBu2(THF)2 with distorted tetrahedral Mg centres. Related imidomagnesium halide complexes can be accessed either by deprotonation of the imine with a Grignard reagent, or nucleophilic addition of a Grignard reagent to a nitrile, but these unusual five-coordinate complexes are unresponsive to a 1,4-dioxane induced Schlenk equilibrium shift. Employing a higher reflux temperature switching from a THF to a toluene medium permits access to the THF solvate of a homoleptic imido complex which also possesses a trinuclear constitution in Mg3(NCPh2)6(THF)2.

Disorders of cervical maturation under wartime stressful conditions

Pregnancy itself is a prerequisite for stress reactions. Even in the physiological course, pregnancy has a certain impact on a woman’s psyche, and some authors even consider it as a crisis situation or a “period of psychological uncertainty”. Women have different types of reactions to pregnancy: from the absence of any psychological problems to neurotic personality development.All the hardships of wartime affect not only the mother’s organism and her psychological state, but also the state of the unborn fetus, which is programmed with certain physical and mental health characteristics for the rest of its life.To prevent these negative effects, pregnant women during the pregravid period and gestation should take preventive measures aimed at strengthening the organism’s defense reactions in adverse conditions. These include a rational nutritious diet, determination of a woman’s personality type by a perinatal psychologist and appropriate psychological practices, and sufficient supplementation of important vitamins and minerals with antioxidant and other protective properties.Pregnancy under the influence of prolonged chronic stress can be complicated not only by purely obstetric and perinatal problems, but also by disorders of the formation of the labour dominant and preparatory processes in the cervix. As a result, this can lead to miscarriage due to the development of tokophobia as a psychological component of these disorders.Cervical maturation before childbirth is a multifactorial process that includes numerous elements, complex processes at the psychological, systemic, tissue, cellular, gene and molecular levels. Comprehensive preparation of a woman’s organism for childbirth in conditions of chronic stress and certain tokophobia (a woman’s fear of childbirth and uncertainty of the future for her and her child during the war) is not only about preventing stressful effects during pregnancy (magnesium complexes with B vitamins – up to the 36th week), conducting a complex of psychoprophylactic therapy and psychophysiological preparation for childbirth from the 37th week, but also in local impact on the cervical state, taking into account changes in connective tissue and correction of the infectious factor at the same time of pregnancy. For this purpose it is advisable and reasonable to prescribe vaginal suppositories based on hyaluronic acid (HA) to accelerate preparatory changes in the cervical tissues by stimulating the synthesis of its own HA and with antibacterial effects due to a complex of plant extracts.

A Well-Defined Magnesium Complex of C70 6.

Controlling and understanding charge state and metal coordination in carbon nanomaterials is crucial to harnessing their unique properties. Here we describe the synthesis of the well-defined fulleride complex [{(Mesnacnac)Mg}6C70], 2, (Mesnacnac)=HC(MeCNMes)2, Mes=2,4,6-Me3C6H2, from the reaction of the β-diketiminate magnesium(I) complex [{(Mesnacnac)Mg}2] with C70 in aromatic solvents. The molecular structure of complex 2 was determined, providing the first high-quality structural study of a complex with the C70 6- ion. In combination with solution state NMR spectroscopic and DFT computational studies, the changes in geometry and charge distribution in the various atom and bond types of the fulleride unit were investigated. Additionally, the influence of the (Mesnacnac)Mg+ cations on the global and local fulleride coordination environment was examined.

Silylation-Driven Volatility Enhancement in Mononuclear Calcium, Magnesium, and Barium Complexes with Monomethyl or Silyl Ether and Bis(diketonate).

Magnesium, calcium, and barium heteroleptic complexes were synthesized by the substitution reaction of the bis(trimethylsilyl)amide of Mg(btsa)2·DME, Ca(btsa)2·DME, and Ba(btsa)2·2DME with an ethereal group and hfac ligands (btsa = bis(trimethylsilyl)amide, DME = dimethoxyethane). The compounds Mg(dts)(hfac)2 (1), Ca(dts)(hfac)2 (2), Mg(dmts)(hfac)2 (3), Ca(dmts)(hfac)2 (4), and Ba(dmts)(hfac)2 (5) were fabricated and analyzed using various techniques, including Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analyses, and elemental analysis (dts = 2,2-dimethyl-3,6,9-trioxa-2-siladecane, dmts = 2,2-dimethyl-3,6,9,12-tetraoxa-2-silatridecane, hfac = hexafluoroacetylacetonate). The structures of complexes 2, 4, and 5 were confirmed using single-crystal X-ray crystallography; all complexes display monomeric structures. All compounds underwent trimethylsilylation of the coordinating ethereal alcohols (meeH and tmgeH) in the presence of HMDS as byproducts because of their increasing acidity originating from the electron-withdrawing hfac ligands. (meeH = 2-(2-methoxyethoxy)ethan-1-ol, tmgeH = tri(ethylene glycol) monoethyl ether, HMDS = hexamethyldisilazane).

Organomagnesia: Reversibly High Carbon Dioxide Uptake by Magnesium Pyrazolates.

A series of new pyrazolate and mixed pyrazolate/pyrazole magnesium complexes is described and their reactivity toward carbon dioxide is examined. The dimeric complex [Mg(pzt Bu, t Bu)2]2 inserts CO2 instantly and quantitatively forming the tetrameric complex [Mg(CO2·pzt Bu, t Bu)2]4 and monomeric donor-stabilized [Mg(CO2·pzt Bu, t Bu)2(thf)2]. Complexes of the type [Mgx(pzR,R)2 x(HpzR,R)y]n (R = iPr, tBu) engage in similar insertion reactions involving dissociation of the carbamic acid HOOCpzR,R. Even solid polymeric derivatives [Mg(pzR,R)2]n (R = Me, H) react instantaneously and exhaustively with CO2, the resulting [Mg(CO2·pz)2]m featuring a CO2 capacity of 35.7wt% (8.2mmol g-1). All described magnesium pyrazolates display completely reversible CO2 uptake in solution and in the solid state, respectively, as monitored via VT 1H NMR and in situ FTIR spectroscopy as well as thermogravimetric analysis. Fluorinated [Mg2(pzCF3,CF3)4(thf)3] does not yield any isolable CO2 insertion product but exhibits the highest activity in the catalytic transformation of epoxides and CO2 to cyclic carbonates.

Adsorption of Cadmium and Lead Capacity and Environmental Stability of Magnesium-Modified High-Sulfur Hydrochar: Greenly Utilizing Chicken Feather.

Chicken feathers represent a viable material for producing biochar adsorbents. Traditional slow pyrolysis methods often result in sulfur element losses from chicken feathers, whereas hydrothermal reactions generate substantial amounts of nutrient-rich hydrothermal liquor. Magnesium-modified high-sulfur hydrochar MWF was synthesized through magnesium modification, achieving a S content of 3.68%. The maximum equilibrium adsorption amounts of MWF for Cd2+ and Pb2+ were 25.12 mg·g-1 and 70.41 mg·g-1, respectively, representing 4.00 times and 2.75 times of WF. Magnesium modification elevated the sulfur content, pH, ash content, and electronegativity of MWF. The primary mechanisms behind MWF's adsorption of Cd2+ and Pb2+ involve magnesium ion exchange and complexation with C=O/O=C-O, quaternary N, and S functional groups. MWF maintains robust stability and antioxidative properties, even with low aromaticity levels. Given the lower energy consumption during hydrochar production, MWF offers notable carbon sequestration benefits. The hydrothermal solution derived from MWF is nutrient-rich. Following supplementation with inorganic fertilizer, the hydrothermal solution of MWF significantly enhanced bok choy growth compared to the control group. In general, adopting magnesium-modified hydrothermal reactions to produce hydrochar and converting the resultant hydrothermal solution into water-soluble fertilizer proves a viable strategy for the eco-friendly utilization of chicken feathers. This approach carries substantial value for heavy metal remediation and agricultural practices.

The Antitumoral Effect In Ovo of a New Inclusion Complex from Dimethoxycurcumin with Magnesium and Beta-Cyclodextrin.

Breast cancer is one of the leading causes of death in the female population because of the resistance of cancer cells to many anticancer drugs used. Curcumin has cytotoxic activities against breast cancer cells, although it has limited use due to its poor bioavailability and rapid metabolic elimination. The synthesis of metal complexes of curcumin and curcuminoids is a relevant topic in the search for more active and selective derivatives of these molecular scaffolds. However, solubility and bioavailability are concomitant disadvantages of these types of molecules. To overcome such drawbacks, the preparation of inclusion complexes offers a chemical and pharmacologically safe option for improving the aqueous solubility of organic molecules. Herein, we describe the preparation of the inclusion complex of dimethoxycurcumin magnesium complex (DiMeOC-Mg, (4)) with beta-cyclodextrin (DiMeOC-Mg-BCD, (5)) in the stoichiometric relationship 1:1. This new inclusion complex's solubility in aqueous media phosphate buffer saline (PBS) was improved by a factor of 6x over the free metal complex (4). Furthermore, 5 affects cell metabolic rate, cell morphology, cell migration, induced apoptosis, and downregulation of the matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), and signal transducer and activator of transcription-3 (STAT3) expression levels on MD Anderson metastasis breast-231 cancer (MDA-MB-231) cell lines. Results of an antitumor assay in an in ovo model showed up to 30% inhibition of tumor growth for breast cancer (MDA-MB-231) when using (5) (0.650 mg/kg dose) and 17.29% inhibition with the free homoleptic metal complex (1.5 mg/kg dose, (4)). While the formulation of inclusion complexes from metal complexes of curcuminoids demonstrates its usefulness in improving the solubility and bioavailability of these metallodrugs, the new compound (5) exhibits excellent potential for use as a therapeutic agent in the battle against breast cancer.

Autonomous Atmospheric Water Harvesting over a Wide RH Range Enabled by Super Hygroscopic Composite Aerogels.

Sorption-based atmospheric water harvesting (SAWH) offers a sustainable strategy to address the global freshwater shortage. However, obtaining sorbents with excellent performance over a wide relative humidity (RH) range and devices with fully autonomous water production remains challenging. Herein, magnesium chloride (MgCl2) is innovatively converted into super hygroscopic magnesium complexes(MC), which can effectively solve the problems of salt deliquescence and agglomeration. The MC are then integrated with photothermal aerogels composed of sodium alginate and carbon nanotubes (SA/CNTs) to form composite aerogels, which showed high water uptake over a wide RH range, reaching 5.43 and 0.27kg kg-1 at 95% and 20% RH, respectively. The hierarchical porous structure enables the as-prepared SA/CNTs/MC to exhibit rapid absorption/desorption kinetics with 12 cycles per day at 70% RH, equivalent to a water yield of 10.0 L kg-1 day-1. To further realize continuous and practical freshwater production, a fully solar-driven autonomous atmospheric water generator is designed and constructed with two SA/CNTs/MC-based absorption layers, which can alternately conduct the water absorption/desorption process without any other energy consumption. The design provides a promising approach to achieving autonomous, high-performance, and scalable SAWH.

Volatile N,N′-dialkyl-β-dialdiminate complexes of magnesium and zinc as possible chemical vapor deposition precursors

A series of volatile magnesium(II) and zinc(II) bis(β-dialdiminato) complexes (of stoichiometry M[RN(CH)3NR]2 where R = methyl, ethyl, isopropyl, or tert-butyl) have been prepared and investigated as potential precursors for the chemical vapor deposition of thin films. Several of the compounds have been characterized crystallographically; the metal centers adopt pseudo-tetrahedral geometries with the two ligands forming six-membered rings with the metal center. All eight compounds sublime cleanly both in vacuum and under 1 atm of N2, and the most volatile compounds (those having N-methyl substituents) have vapor pressures of 1 Torr at 88 (Mg) and 90 °C (Zn). In general, metal complexes of N,N′-dialkyl-β-dialdiminate ligands are more volatile than their corresponding N,N′-dialkyl-β-diketiminate and N,N-dialkylamidinate analogues.

Structural characterization of fatty acid anions via gas-phase charge inversion using Mg(tri-butyl-terpyridine)2 2+ reagent ions.

Free fatty acids and lipid classes containing fatty acid esters are major components of lipidome. In the absence of a chemical derivatization step, FA anions do not yield all of the structural information that may be of interest under commonly used collision-induced dissociation (CID) conditions. A line of work that avoids condensed-phase derivatization takes advantage of gas-phase ion/ion chemistry to charge invert FA anions to an ion type that provides the structural information of interest using conventional CID. This work was motivated by the potential for significant improvement in overall efficiency for obtaining FA chain structural information. A hybrid triple quadrupole/linear ion-trap tandem mass spectrometer that has been modified to enable the execution of ion/ion reaction experiments was used to evaluate the use of 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine (ttb-Terpy) as the ligand in divalent magnesium complexes for charge inversion of FA anions. Mg(ttb-Terpy)2 2+ complexes provide significantly improved efficiency in producing structurally informative products from FA ions relative to Mg(Terpy)2 2+ complexes, as demonstrated for straight-chain FAs, branched-chain FAs, unsaturated FAs, and cyclopropane-containing FAs. It was discovered that most of the structurally informative fragmentation from [FA-H + Mg(ttb-Terpy)]+ results from the loss of a methyl radical from the ligand followed by radical-directed dissociation (RDD), which stands in contrast to the charge-remote fragmentation (CRF) believed to be operative with the [FA-H + Mg(Terpy)]+ ions. This work demonstrates that a large fraction of product ions from the CID of ions of the form [FA-H + Mg(ttb-Terpy)]+ are derived from RDD of the FA backbone, with a very minor fraction arising from structurally uninformative dissociation channels. This ligand provides an alternative to previously used ligands for the structural characterization of FAs via CRF.

Clinical Effects and Functional State of the Endothelium in Patients with Arterial Hypertension with a Suboptimal Level of K+ in the Dynamics of Treatment with a Potassium-Magnesium Mineral Complex

Today, electrolyte dysbalance plays an important role in the formation and progression of cardiovascular diseases. The risk of development cardiovascular events also depends on potassium and magnesium deficiency. However, the issue of risks and clinical consequences of suboptimal serum potassium remains poorly understood. The objective: to analyze the influence of the mineral complex on the clinical status, serum levels of potassium and magnesium and the functional state of the endothelium, heart rhythm and parameters of the blood lipid spectrum in patients with arterial hypertension (AH) of the 2nd grade. Materials and methods. 60 patients from 43 to 65 years old with grade 2 AH, II stage took part in the study. Patients (36 men and 24 women) were divided into two groups of 30 persons each. Patients of the 1st group received antihypertensive therapy (perindopril 5–10 mg/day or valsartan 80–120 mg/day + hydrochlorothiazide 12.5 mg) and atorvastatin 20 mg/day. Patients of the 2nd group, in addition to the above-mentioned therapy, were prescribed a mineral complex of natural potassium and magnesium, 1 sachet per day for 3 months. Endothelial function was examined for all participants, the peak blood flow index was determined, arterial blood pressure (ABP) and electrocardiogram (ECG) were monitored daily. Results. In patients of the 2nd group, gradual increased levels of K+ and Mg+ in the blood plasma were determined: the median level of K+ increased by 25.9%, and the median Mg+ concentration – by 16.4% (р˂0.01). Endothelium-dependent vasodilatation after three months of potassium-magnesium citrate use became 2.17 times higher than the initial indicator and 1.94 times higher than in the 1st group (p<0.05). In the 2nd group of patients who additionally took the mineral complex, statistically significant positive dynamics of the blood pressure level were found: after 3 months, the median daily systolic blood pressure (SBP) decreased to 133.56 mm Hg. (LQ=131.64; HQ=135.29) (p<0.01). A significant decrease in the medians of both day and night SBP and diastolic blood pressure was also determined (p<0.01). At the same time, compared to the initial values, the number of ectopic arrhythmias decreased: supraventricular extrasystoles – by 47%, single and paired ventricular extrasystoles – by 37.5% and 47.1%, respectively (p<0.01). Positive dynamics of lipid indicators were found in the patients of the 2nd group. Conclusions. Prescribing a mineral complex to patients with AH and a suboptimal level of K+ who receive therapy including a thiazide diuretic has a complex positive effect: it increases the effectiveness of antihypertensive and hypolipidemic therapy, improves the functional state of the endothelium and vasodilatation, reduces the number of heart rhythm disorders and prevents the occurrence of hypokalemia and hypomagnesemia.

Gas-Phase Ion/Ion Reactions to Enable Radical-Directed Dissociation of Fatty Acid Ions: Application to Localization of Methyl Branching.

Methyl branching on the carbon chains of fatty acids and fatty esters is among the structural variations encountered with fatty acids and fatty esters. Branching in fatty acid/ester chains is particularly prominent in bacterial species and, for example, in vernix caseosa and sebum. The distinction of branched chains from isomeric straight-chain species and the localization of branching can be challenging to determine by mass spectrometry (MS). Condensed-phase derivatization strategies, often used in conjunction with separations, are most commonly used to address the identification and characterization of branched fatty acids. In this work, a gas-phase ion/ion strategy is presented that obviates condensed-phase derivatization and introduces a radical site into fatty acid ions to facilitate radical-directed dissociation (RDD). The gas-phase approach is also directly amenable to fatty acid anions generated via collision-induced dissociation from lipid classes that contain fatty esters. Specifically, divalent magnesium complexes bound to two terpyridine ligands that each incorporate a ((2,2,6,6-tetramethyl-1-piperidine-1-yl)oxy) (TEMPO) moiety are used to charge-invert fatty acid anions. Following the facile loss of one of the ligands and the TEMPO group of the remaining ligand, a radical site is introduced into the complex. Subsequent collision-induced dissociation (CID) of the complex exhibits preferred cleavages that localize the site(s) of branching. The approach is illustrated with iso-, anteiso-, and isoprenoid branched-chain fatty acids and an intact glycerophospholipid and is applied to a mixture of branched- and straight-chain fatty acids derived from Bacillus subtilis.

Magnesium‐Catalyzed Asymmetric Thia‐Michael Addition to α,β‐Unsaturated Ketones

AbstractWe demonstrate the application of chiral magnesium complexes in an asymmetric carbon‐sulfur bond‐forming reaction. Enantioselective and cost‐effective methodology under mild condition for the thia‐Michael addition, utilizing an in situ generated chiral dinuclear magnesium‐ProPhenol complex, has been developed. The versatility of this protocol is demonstrated with a broad range of thiol nucleophiles and a wide selection of enones. Enantioenriched β‐ketosulfides are obtained in good to excellent yields and moderate to excellent enantioselectivity. The presented catalytic system exhibits excellent tolerance for structurally different substrates while maintaining high enantioselectivity. This observation aligns with proposed mechanism, wherein the sulfur atom coordinates to the catalyst in close proximity to the reaction center.

Stabilization and One Electron Reduction of a Silicon Analogue of a Carboxylic Acid Anhydride.

Reaction of the 1,2-disilylenes {(DipAr Am)Si}2 (DipAr Am=[(NDip)2 CAr]- , Dip=2,6-diisopropylphenyl, Ar=4-C6 H4 But (Ar') 1 a or Ph 1 b) and two abnormal N-heterocyclic silylenes, (DipAr Am)SiOCSi{(NDip)2 CAr} (Ar=Ar' 3 a or Ph 3 b) with N2 O led to formation of unprecedented examples of uncoordinated silicon analogues of carboxylic acid anhydrides, (DipAr Am)(O=)SiOSi(=O)(DipAr Am) (Ar=Ar' 2 a or Ph 2 b). Both compounds have been fully characterized, and the mechanism of formation of one explored using DFT calculations. Reduction of sila-acid anhydride 2 a with a dimagnesium(I) compound, [{(Mes Nacnac)Mg}2 ] (Mes Nacnac=[(MesNCMe)2 CH]- , Mes=mesityl), led to the one-electron reduction of the anhydride and formation of a magnesium complex of a sila-acid anhydride radical anion [(Mes Nacnac)Mg{(OSi(DipAr' Am)}2 O] 5. A combination of EPR spectroscopic studies and DFT calculations reveal the unpaired electron to largely reside on one of the amidinate ligands of the complex.

Fluorenyl-tethered N-heterocyclic carbene: An effective ancillary support for heteroleptic magnesium organometallics

Judicious designing of ancillary ligands with appropriate stetrolelectronics is critical for the chemistries of electropositive alkaline earths that typically make labile coordination to conventional donor sites. We report here a series of magnesium complexes [(LH)Mg(A)Br(thf)] (A = nBu (1), N(SiMe3)2 (2)), [(L)Mg{N(SiMe3)2}] (3), and [(L)MgMe(thf)] (4) supported by a N-heterocyclic carbene LH ([(Flu)H-(CH2)2-NHCDipp]; Dipp = 2,6-iPr2-C6H3) with a fluorenyl sidearm and its monoanionic version L- ([(Flu)-(CH2)2-NHCDipp] -). Complexes 1, 2, and 4 are characterized by single crystal X-ray diffractometry. 3 and 4 are additionally analyzed by DFT calculations. The pseudo-bidentate L- appears to be quite an effective ancillary support as evident from the monomeric nature of 4 and the thermal stability of 3 and 4 towards the deleterious Schlenk equilibrium. This is also reflected in 4′s catalytic activity in intramolecular hydroamination/cyclization of two primary aminoalkenes as model substrates, for which the presence of a spectator ligand and its ability to thwart the Schlenk equilibrium are critical. It’s also the 1st NHC-based main group catalyst for intramolecular hydroamination. Complex 2 also catalyzes the hydroboration of model substrates of carbonyl, ester, amide, and nitrile functions.

Bioactive porphyrin magnesium (II) complex. Synthesis, molecular structure and spectroscopic characterization. Biological activity and molecular docking studies

We have synthesized and characterized porphyrin structures by UV–visible, IR and fluorescence spectroscopy studies and single crystal XRD analysis; H2(TPP) (I) (meso-tetraphenylporphyrin), [Mg(TPP)(DMF)] (II); (DMF: dimethylformamide) and [Mg(TPP)(H2O)]0.2(4-CNpy) (III); (4-CNpy: 4-Cyanopyridine). The crystal packing of the porphyrin structures is stabilized by intermolecular hydrogen bonds and by intermolecular CH⋯Cg π interactions where Cg is the centroid of the phenyl and pyrrole rings. UV–Vis spectroscopic data confirmed the creation of Mg-meso-porphyrin complexes by the red-shifted Soret bands for our derivatives compared to the free-base porphyrin. The optical gap energy values of (I), (II) and (III) are 1.92, 2.07 and 2.00 eV. Gram-positive and Gram-negative bacteria were tested against free porphyrin (I), metallated porphyrin (II) and complex (III). The results show that the magnesium porphyrin derivative is highly effective compared to H2TPP free-base porphyrins and metallated porphyrin [Mg(TPP)] and has higher inhibition character against the tested bacteria. The molecular docking of the complex (III), in the active sites of bacterial proteins was carried out to detect the degree of antibacterial activity of recognition.

Reactivity of Mg(AlMe4)2 towards neutral tris(pyrazolyl)alkanes.

Various new tris(pyrazolyl)alkanes of the class R'CTp3-R (R' = Me, Et, nPr, iBu; R = Et, cyPr, Cy, p-tBuPh, Ph; cyPr = cyclopropyl, Cy = cyclohexyl, p-tBuPh = para-tert-butylphenyl) were synthesised and their reactivity towards Mg(AlMe4)2 was examined. Along with new examples of recurring structural motifs, such as separated ion pairs and "metal in a box" complexes, e.g., [(MeCTp3-Et)2Mg][AlMe4]2, several magnesium complexes with new structural features/compositions were obtained. Treatment of the "metal in a box" species [(MeCTp3-R)Mg][AlMe4]2 with THF donor gave the terminal methyl complex [(MeCTp3-cyPr)MgMe(thf)2][AlMe4]. Variation of the backbone alkyl substituent R' in the tris(pyrazolyl)alkane R'CTp3-Ph gave ionic liquids (R' = Et, nPr) and the methyl-bridged dimagnesium complex [({iBuCTp3-Ph}Mg{AlMe4})2(μ-Me)][AlMe4]. The bulky Cy and p-tBuPh moieties at the pyrazolyl 3 position gave the new structural motif [MeCTp3-RMg(ηn-AlMe4)][AlMe4] (η3, R = Cy; η2, R = p-tBuPh), stabilising a "[Mg(AlMe4)]+" entity. The AlMe3 group can be reversibly displaced under reduced pressure affording the new separated ion pair [(MeCTp3-p-tBuPh)MgMe][AlMe4] with a terminal "[MgMe]+" moiety. Moderate thermal treatment of both [(MeCTp3-p-tBuPh)MgMe][AlMe4] and [(MeCTp3-p-tBuPh)Mg(η2-AlMe4)][AlMe4] resulted in selective C-H-bond activation in the 5 position of one of the pyrazolyl moieties and the formation of an AlMe3-modified anionic tris(pyrazolyl)alkane and hence the neutral complex [MeC(pz3-p-tBuPh)2(pz3-p-tBuPh,5-AlMe3)]MgMe.

SYNTHESIS AND PROPERTIES OF PERIPHERALLY AND NONPERIPHERALLY SUBSTITUTED ZINC AND MAGNESIUM PHTHALOCYANINES BASED ON 3/4-(4-BROMO-2-((4-METHOXYPHENYL)DIAZENYL)PHENOXY)PHTHALONITRILE

The work describes the optimization of the procedure for the synthesis of 4-bromo-2-methoxyphenyldiazenylphenol, which is used as a nucleophile in the presence of 3- and 4-nitrophthalonitriles. The resulting 3-(4-bromo-2-((4-methoxyphenyl)diazenyl)phenoxy)- and 4-(4-bromo-2-((4-methoxyphenyl)diazenyl)phenoxy)phthalonitriles were used for template condensation with magnesium or zinc acetate. Methods for isolating and purifying the synthesized compounds are described. The structure and composition were confirmed using IR, 1H NMR and electron spectroscopy. Peripheral functionalization of macrocycle by a conjugate azochromophore fragment gives molecules phthalocyanine with special optical properties. This class of phthalocyanines containing an additional chromophore system in their composition is attractive for potential use not only as pigments and dyes traditional for phthalocyanine compounds, but also as chemical sensors, dye-sensitized solar cells and photosensitizers for PDT. The resulting nitriles and phthalocyanine complexes dissolve in chloroforms, toluene, THF, and DMF. The influence of the substituent location on the spectral properties of the obtained metal complexes (Zn, Mg) in organic solvents has been studied. For non-peripherally substituted metal phthalocyanines, acid-base properties are studied. To observe and study the acid-base effect, spectrophotometric titration of the trifluoroacetic acid complex in toluene is used. It is shown that the magnesium complex is more basic than the zinc complex. In this work, the luminescent properties are also studied and the quantum yields of singlet oxygen formation for synthesized complexes in THF are determined. The influence of the substituent location on the quantum yield of fluorescence, as well as on the generation of singlet oxygen, is noted in the work.